Electric switch



E. VOSSEN ELECTRIC SWITCH Filed Dec.

July 21, 1959 INVENTOR EDWARD VOSSEN BY ATTORNEY.

ELECTRIC SWITCH Edward Vossen, Malverne, N.Y., assignor to Stop Motion Devices Corp., Brooklyn, NY.

Application December 23, 1957, Serial No. 704,380

2 Claims. (Cl. 200-51) This invention relates to an electric switch.

The electric switch herein described and claimed consists essentially of an inner contact member which is completely surrounded by an outer contact member, the two members being insulated from each other, and either of said members being exible and movable into and out of engagement with the other of said members. One of the contact members, usually but not necessarily the inner contact member, is relatively rigid. The other contact member, usually but not necessarily the outer contact member, is exible. The switch may be normally closed or normally open. When normally closed, the two contact members are in engagement with each other, and contact may be broken by moving the relatively flexible member, which is usually the outer one, away from the relatively inexible contact member, usually the inner one. When the switch is normally open, it may be closed by moving the relatively exible member, again usually the outer member, into engagement with the relatively inexible member, again usually the inner member.

The invention will be described in the specification and shown in the drawing mainly in connection with a switch which is normally open. However, modifications of this structure will also be described and shown, wherein the switch is normally closed.

There are many features and advantages in this device which enable it to be used in so many different applications, as follows:

(l) In the first place, the switch is operable through a range of a full 360 degrees. The outer tubular contact member is adapted to ex in any radial direction oriented from the central axis of the switch, which is the longitudinal axis of the inner contact member. Since the outer contact member is concentric with the inner member, this is also the longitudinal axis of said outer contact member. In short, the outer contact member will engage the inner contact member and close the switch irrespective of the direction in which the exing of said outer contact member takes place.

(2) Flexing of the outer contact member may be limited to a predetermined area of movement within a predetermined and restricted angular range. For example, it may be desired to block liexing of the outer contact member within an arcuate range of 300 degrees, leaving said contact member free for flexing in the remaining 60 degrees. By the same token, it may be desired to provide the outer contact member with freedom of movement in a plurality of spaced areas, in which case blocking means would be provided intermediate these areas. Again by way of illustration, exing may be blocked within an arcuate range of 100 degrees, and within the succeeding range of 80 degrees exing may be permitted. Again, there may be 100 degrees of blockage and nally another 80 degrees of freedom of movement, making a total of 360 degrees. In such case, the flexing would be limited to two diametrically opposed areas, each covering a range of 80 degrees.

(3) The switch is adjustable and flexible in still another sense. lt is possible to predetermine the extent of iiexing of the outer contact member which would be required to bring it into engagement with the inner contact member. For example, it may be desired that tiexing to the extent of only 10 degrees will suice for making contact, or it may just as readily be desired that flexing to the extent of 45 degrees be required before contact takes place. These variations and adjustments may be effectuated through a variety of means. The spacing between the inner and outer contact members is one factor that may be varied to modify the extent of exing necessary to produce contact. Another factor is the extent to which the inner contact member projects into the uninsulated part of the outer contact member. In one form of this invention, the inner contact member is adjustably mounted within the insulation separating the two contact members. This adjustment renders it possible to project or retract the inner contact member relative to the outer contact member to any desired extent. v

(4) Another feature is the inherent tension which is built into the outer contact member. This inherent tension normally maintains the outer contact member in inoperative position, out of engagement with the inner contact member. This tension also tends to resist flexing of the outer contact member into engagement with the inner contact member, and by the same token it returns the outer contact member to its normal inoperative position as soon as it is released.

(5) The last feature above mentioned may be adjusted in the sense of predetermining the ex resistance of the outer contact member, and consequently this would also determine its predisposition to return to its normal uniexed condition. The outer contact member is a spring, and conventional means and methods may be used to predetermine the spring tension therein. This would determine the flex resistance of said outer contact member.

(6) An important feature of this invention is the fact that the switch may be made normally closed, so that the flexing of the outer contact member would cause it to open. This feature may be achieved in various ways. For example, the outer contact member may be prestressed or preformed so as to normally contact the inner contact member. It would require exing of the outer contact member to disengage it from the inner contact member. Another possibility is to preform the inner contact member so that it will engage the outer contact member when the latter is in its normal unliexed position. Again, it would require exing of the outer member to disengage it from the inner.

(7) An important feature of the present switch is its wiping action. Among the many applications of the switch is its use in connection with stop motion devices or knitting machines. Lint is a serious problem in such installations, and a wiping action is almost essential if the switch is to retain its efficiency over a period of time. In the present case, exing of the outer contact member into engagement with the inner contact member causes the individual convolutions of the outer member to slide across the face of the inner contact member, thereby producing a wiping action. Unilexing of the outer contact member reverses this procedure and causes a wiping action in reverse direction. Both contact members are thereby kept clean by their very use.

(8) Still another important feature of this device is its silent operation. Flexing of the outer contact member is utterly soundless, and the wiping contact of its convolutions with the inner contact member is virtually equally soundless. The human ear cannot detect the sounds produced by this wiping action. While silent operation of the switches in a knitting machine is totally unrewarding, for the reason that the knitting machine itself produces so much noise, in many applications of the present invention such silent operation is a desirable and even necessary feature.

The invention is illustrated in the accompanying drawing, in which:

Fig. 1 is a longitudinal section through a switch made in accordance with this invention, the outer contact meme ber being shown in unflexed condition and out of engagement with the inner contact member.

Fig. 2 is a longitudinal section on the line 2-2 of Fig. 1, showing the outer contact member tiered into engagement with the inner contact member.

Fig. 3 is a view similar to that of Fig. 2, but showing the result of further iiexing of the outer contact member to indicate how the wiping action takes place.

Fig. 4 is a cross-section on the line i 4- of Fig. l.

Fig. 5 is a sectional View showing a modified construction of the present device, wherein the inner contact member is adjustably mounted relative to the outer contact member.

Fig. 6 is another sectional View of a modified form of this invention, wherein the inner contact member is shown -to be preformed for engagement with the outer contact member when the latter is in its unfiexed condition.

Fig. 7 is a Sectional view of another modification of this invention, wherein the inner Contact member is shown to be relatively flexible and movable into and out of engagement with the outer contact member.

Referring now to the first form of this invention and to Figs. l to 4, inclusive, it will be seen that switch 1@ made in accordance with this invention comprises the following component parts: an inner contact member 12, an outer contact member 14, and insulation 16 disposed between the two contact members. More specifically, inner contact member 12 is simply a metal rod or wire with its inner or operative end 12a suitably rounded off to provide a suitable contact face or area for engagement with the other contact member 14. The outer end of rod 12 may be secured to a clip or fitting 13 for attachment to a binding post or other terminal or the like. In this form of the invention, rod 12 is a straight member, at least that portion of it which cooperates with the outer contact member 14, as will hereinafter be seen.

The outer contact member 14 is a helical coil spring which is normally disposed in concentric relation to the rod or inner contact member 12. Insulation 16 is simply an insulating sleeve which separates and spaces the coil spring or outer contact member 14 from the rod or inner contact member 12.

It will now be noted that the rounded end 12a of rod 12 projects upon insulating sleeve 16 in order to provide access to the coiled contact member 14. An outer sleeve or ferrule 18 Secures one end of the coiled contact member 14 to the insulating sleeve 16. A fitting 2t) is secured to the opposite end of said coiled contact member, as by means of solder or any other conventional means. The opposite or free end of fitting 20 is a clip 20a by which the fitting may be attached to a binding post or the like.

The operation of this device is clearly shown in Figs. l, 2 and 3. Fig. l shows the switch in open condition, wherein rod 12, insulating sleeve 16 and coil 1d are all disposed in concentric relation to each other. There is no contact between the rod and the coil. When it is desired to close the switch, coil 14 is fiexed from its Fig. 1 position to its Fig. 2 position and thence to its Fig. 3 position. Contact between rod 12 and coil 14 takes place as soon as flexing of the coil reaches the Fig. 2 stage, but at this point the contact is merely an abutting of one member against the other, without a wiping action. The wiping action takes place when the coil is flexed beyond its Fig. 2 position and into the position which it is shown to occupy in Fig. 3. It will be noted that the third and fourth convolutions beyond the insulating sleeve 16 are in contact with rod 12 in Fig. 2. In Fig. 3, however, the convolutions are spread farther apart, and contact is made between the rod on the one hand and the second and third convolutions on the other, the fourth convolution being completely removed from engagement with the rod. This clearly evidences that a wiping action takes place, in which the several convolutions of the coil wipe their way along the curved end 12a of rod 12. When the coil is fiexed backwardly to its Fig. l position, it passes through the Fig. 2 stage and once again a wiping action takes place, but this time in reverse order or direction.

It will be observed that rod 12 is fixed in position relative to the insulating sleeve 16 in the first four figures of the drawing. This position is one of the factors in determining the extent of iiexing necessary to bring the coil into contact with the rod. The radial spacing between the rod and the coil will also be a factor in determining this matter, and this spacing is itself controlled by the thickness of the insulating sleeve. It will also be observed that in this form of the invention the coil may flex in any radial direction within the full range of 360 degrees about the axis of rod 12. Contact between the parts will be made irrespective of the direction of iiexing of the coil.

A variation of the foregoing is shown in Fig. 5, wherein insulating sleeve 30 is provided with internal screw threads 32, which receive external screw threads 34 of rod 36. Rod 36 may be rotated relative to sleeve 30 in order to project the rounded forward end 36a of the rod forwardly, or to retract the same, depending upon the direction of rotation of said rod. This will determine the angle at which the fiexed coil 38 will engage the rod.

it will also be noted in Fig. 5 that sleeve or ferrule 40 which secures the coil to the insulating sleeve 30 is provided with an outwardly projecting lug 42. This lug abuts the coil and prevents iiexing in the direction of said lug. As has above been indicated, this lug, or a plurality of such lugs, may be used to limit the range and direction of flexing of the coil.

Fig. 6 shows a switch Si) which is basically like that of the first four figures of the drawing, except that its rod 52 has a laterally bent end 54. This end S4 normally contacts coil 56 when the coil is in uniiexed condition. Consequently, switch 50 is a normally closed switch, and it requires fiexing of the coil to disengage it from the rod.

It should also be understood that coils may be pre formed so as to occupy a position such as is shown in Fig. 3 when in completely relaxed state. In such case, the switch would also be normally closed, since the coil would normally engage the rod. It would require flexing of the coil from its Fig. 3 position to its Fig. l position in order to breakl the Contact. Under such conditions, once the coil is released it would revert to its preformed or prestressed condition, as shown in Fig. 3. Normally, however, the relaxed position of the coil would be as shown in Fig. l, and the variation last above described would simply be a modification of this condition.

The foregoing is illustrative of preferred forms of this invention, and it will be understood that these preferred forms may be modified and other forms may be provided within the broad spirit of the invention and the broad scope of the claims.

For example, the modification shown in Fig. 7 indicates that they inner Contact member may be made relatively flexible and the outer contact member relatively rigid, so as to enable the inner contact member to move into and out of engagement with the outer contact member. Specifically, the inner contact member 6ft is now shown to be a helical coil spring, and the outer contact member 62 is shown to be a relatively rigid' tube. An insulating sleeve 64 separates the two, but, when the inner member 6) is iiexed laterally, it will engage the outer member 62 and thereby close the switch. Conversely, the inner Contact member 61) may be flexed in the opposite direction to disengage it from the outer Contact member, and thereby to open the switch. As is the case with the other switches abovedescribed, this form ofthe invention may be made normally open or normally closed.

I claim:

1. An electric switch of the character described, comprising a straight wire, an insulating sleeve on said straight wire, a spaced distance from one end of said wire, leaving said end bare, and a coil spring surrounding said insulating sleeve and said wire, one end of said coil spring being secured to said insulating sleeve and the opposite end being adapted to ex relative to its longitudinal axis into and out of engagement with the bare end of said wire, the straight wire being provided with external screw threads and the insulating sleeve with internal screw threads meshing therewith, whereby the wire is longitudinally adjustable relative to the insulating sleeve and the coil spring.

2. An electric switch of the character described, comprising a straight wire, an insulating sleeve on said straight wire a spaced distance from one end of said wire, leaving said end bare, and a coil spring surrounding said insulating sleeve and said wire, one end of said coil spring being secured to said insulating sleeve and the opposite end being adapted to ilex relative to its longitudinal axis into and out of engagement with the bare end of said wire, the straight wire being provided with external screw threads and the insulating sleeve with internal screw threads meshing therewith, whereby the wire is longitudinally adjustable relative to the insulating sleeve and the coil spring, the bare end of the straight wire being provided with a laterally bent portion which is normally in engagement with the coil spring, said coil spring being adapted to flex out of engagement therewith.

References Cited in the tile of this patent UNITED STATES PATENTS 1,580,782 Gross Apr. 13, 1926 2,208,697 Kernodle et al July 23, 1940 2,270,687 Morse Ian. 20, 1942 2,482,630 Mastromarino Sept. 20, 1949 2,592,742 Rose Apr. 15, 1952 2,813,940 Poet Nov. 19, 1957 

